Expertise documents

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Balanced nutrition for a healthy alcoholic fermentation

Nitrogen is an essential nutrient for smooth alcoholic fermentation (AF). Numerous  studies have shown that nitrogen has a positive impact on the growth and fermentation activity of yeast (Bell et al. 1979, Ough and Lee 1981, Bezenger and Navarro 1987). Deficiencies in yeast-available nitrogen (YAN) in the must significantly increase the risk of sluggish or stuck fermentations because they can arrest protein synthesis in the yeast cells. We consider a must with an initial sugar level of about 200 g/L to be deficient when its YAN concentration is about 150 mg/L (Henschke and Jiranek 1993). A YAN deficiency in the must can also cause the yeast to increase the production of H2S (Henschke and Jiranek, 1991). This edition of the Winemaking update focuses on the impact of balanced nutrition on alcoholic fermentation.

Lallemand Winemaking Update #13 2010 - Balanced nutirtion

Rosé Fermentation

In 2006, the world production of rosé wines was estimated at 21.5 million hL – 9% of the total world production of wine (Aigrain 2009). Production has been increasing for several years. In the United Kingdom, for example the main sellers are rosé wines from the United States – almost half of the total wines sold in supermarkets. From a technical point of view, the production of rosé wine involves particular considerations as rosé is mid-way between white wine (avoiding the extraction of phenolic compounds at the tannin level) and red wine (involving potential problems with colour extraction and structure). When short maceration times are used in the production of high quality rosé wines, the wines can be fragile and evolve rapidly. One of the most frequent developments is the appearance of premature lactic and creamy aromas that can override the fruity aromas in the nose and the refreshing sensation in retronasal perception. This issue of Winemaking Update focuses on some points to consider during fermentation - please click on the link to see the full articleWUP #2- 2012 Rosé Australie